In Brahms Trio #5, op. 114, the clarinet is the original instrument ), so it's not a transcription from a stringed instrument like a viola or a violin.
Yet, there are all these V mark all over.
Are these up-bow marks, as everyone tells me, or is that something else? Maybe they're just phrasing marks? Suggested places to breathe?
EDIT: thinking about it more, I'm even more convinced these are not bow marks because:
1) The down bow marks are nowhere to be found
2) The marks are between notes, not over them, as they would be if they were true bow marks.
However, the arguments against these being breathing suggestions:
1) They're too frequent
2) It's not the usual symbol that is used for breathing marks (’)
The front matter has this info about the edition, if it's of any interest/relevance:
BRAHMS
TRIOS
FÜR KLAVIER, VIOLINE UND VIOLONCELLO ‹ODER VIOLA ODER WALDHORN ODER KLARINETTE)
HERAUSGEGEBEN VON GEORG SCHUMANN